Bridge-type precision antenna structure



5 Sheets-Sheet l wwwa May 13, 1952 K. A. ALLEBACH BRIDGE-TYPE PRECISION ANTENNA STRUCTURE Filed sept. 1s, 194e May 13, 1952 K. A. ALLEBACH BRIDGE-TYPE PRECISION ANTENNA STRUCTURE Filed Sept. 18. 1948 5 Sheets-Sheet 2 Tllllll I l I Il May 13, 1952 K. A. ALLEBAcl-l BRIDGE-TYPE PRECISION ANTENNA STRUCTURE 5 Sheets-Sheet 3 Filed Sept. 18. 1948 May 13, 1952 K. A. ALLEBAcH 2,596,113

BRIDGE-TYPE PRECISION ANTENNA STRUCTURE Filed Sept. 18. 1948 5 Sheets-Sheet 4 14 ;:ii; iii I 5 110 33045 50 100 /777 .f

71 40d F1 .11 W05 448 U J' z5 F13 14 45 1o W44 M511 I! .Egx I 43 47 m au@ 3B May l3, 1952 K. A. ALLEBAcl-l 2,596,113

' BRIDGE-TYPE PRECISION ANTENNA STRUCTURE Filed Sept. 18. 1948 5 Sheets-Sheet 5 .l man 9 '[30 --HIHHI hh mi W Y/ n ,6B/Gi /68 Patented May 13, 1952 BRIDGE-TYPE PRE CISION ANTENNA STRUCTURE Karl A. Allebach, Los Angeles, Calif., assigner to Gilfillan Bros., Inc., Los Angeles, Calif., a corporation of California Application September 18, 19478, Serial No. 49,910

l 19 Claims.

The present invention relates to an improved variable cross section wave guide arranged to feed a plurality of dipoles in, for example and (Cl. Z50-33.63)

not as a limitation, ground control approach systems (GCA).

Variable cross section wave guides have previously been used to feed a plurality of dipoles in an array. Such prior art Wave guides were relatively diicult and expensive to manufacture and to assemble and to maintain in use.

Itis, therefore, an object of the present invention to provide an improved wave guide which is relatively easy to manufacture and assemble and to maintain in working condition.

Another object of the present invention is to provide an improved wave guide characterized by the fact that various portions of the guide may be adjusted independently of other portions whereby the wave guide may be adjusted for uniform dimensions throughout its length or for achievement of desired radiation characteristics.

Another object of the present invention is to provide an improved variable cross section wave guide in which the wearing surfaces are readily accessible and interchangeable whereby the wave guide may be conveniently serviced while in use in the eld.

Still another object of the present invention is to provide an improved variable cross section wave guide having one movable element thereof adjustable in two directions at different regions along its length whereby the cross section may be adjusted to be uniforzn throughout its entire length.

AYet another object of the present invention is to provide an improved variable cross section wave guide characterized by the fact that the movable element thereof is movably mounted on a conveniently accessible bridge element.

Still another important object of the present invention is to provide an improved variable cross section wave guide characterized by the comparative ease with which the A dimension and/or B clearance may be adjusted.

Yet another important object of the present invention is to provide an improved variable cross section wave guide with themovable wave guide member supported on a bridge structure and associated tracks and bearings characterized by the fact that the bridges may be easily removed andthe bearings and/or tracks may bereplaced or cleaned independently of one another.

AYet another important object of thevpresent invention is to provide an improved variable cross section wave guide comprising a movable wave guide member and a relatively stationary wave guide member characterized by the fact that by removing conveniently accessible bridge supporting members, the interior of the wave guide may be conveniently inspected and cleaned and thereafter such supporting bridge members mounted in place again without disturbing appreciably the initial A dimension and/or B clearance adjustment of the wave guide.

Still a further object of the present invention is to provide an improved wave guide, the interior of which, by disassembling, may be conveniently inspected and cleaned, as the occasion arises, and then reassembled withoutV disturbing the initial adjustment of the critical dimensions in the wave guide.

The `features of the present invention which are believed to be novel are set forth with particularity in the appended claims. This invention itself, both as to its organization and Inann'er of operation, together with further objects and advantages thereof, may be best understood by reference to the following description taken in connection with the accompanying drawings in which: l

Figure 1 is a plan view of a variable cross section wave guide arranged to feed a plurality of dipoles embodying the features of the present invention. j i

Figure 2 is a View in elevation showing the other side of the wave guide shown in Figure 1.

Figures 3, 4, 5 and 6 taken collectively-show progressive sections of the wave guide of Figure 2 in enlarged form, the 'individual sections in Figures 3, 4, 5 and 6 being formed together in that order as indicated'by the arrows.

Figure 7 is a View in side elevation taken in the directionY indicated by the arrow 1-1 in Figures 1 and 3.

VFigure 8 is a sectional view taken on the line 8-8 of Figure 5.

Figure 9 is a sectional view taken substantially on the line 9 9 of Figure 8.

Figure 10`is alsectionalyiew taken substantially on the line lll-l0 of Figure 5.V

Figure 11 is a sectional view taken substantially on the line lI-ll of Figure 10.

Figure 12 is a sectional view taken substantially on the line l2'-|2 of Figure '710.

Figure 13 is a sectional view taken substantially on the'line |3--l3 of Figure 5."

Figure 14 is a sectional view taken substantially on theline Ill-I4 of Figure 13.

Figure, 15 is a view taken in the direction indicated by the arrows I5-I5 in Figure 13 of a portion of the antenna structure.

Figure 16 is a sectional view taken substantially on the line I6-I6 of Figure 3.

Figure 17 is a View in elevation of one of the dipoles showing the manner in which it is mounted on the wave guide. o

Figures 1'8A and 1'9 are respectively a'sectional view and 'a perspective view of the dipole shown in Figure 17.

Figure 20 is a perspective view of the end of the wave guide structure partly fragmented.

Figure 21 is a perspective view of one of the hardened surfaces supporting members attached to the movable guide section.

The wave guide comprises essentially two parts, namely, a relatively stationary member I0 and a relatively movable member I I, the member II being reciprocable in the so-called A dimension or in the direction indicated by the arrows I3 in Figure 13 to maintain the internal variable c'rcs's 'sectional area I 4 of the wave guide rec. tangular a't all times. This so-called A-dimension is lthe'distance, in Figure 13, between the walls IDB, `IIB 'of the cooperating wave guide members ill), 'I-I. This A-dimension, of course, varis with yvariation in position of the movable wave guide member II.

The'movable wave guide member II is so supported that it is adjustable at different positions along its lengthlin two mutually perpendicular 'directions corresponding to the axes of the rectangular areal` to 'assure the same cross sectional area I'4"along the length of the guide. The mannerin wh'ic'h'suc'h member II is adjustably supported to produce this result is of importance in the action described in detail hereinafter. Also, since the movable element II is relatively lo'ig andfheavyjfit, must have suitable bearing surfaces'which, inaccordance with one of the features ofthe present' invention, are easily accessible and easily vmp1aceame in the held.

As shown'fi'n'Figure 13, the wave guide area is denedon the one hand by perpendicular faces IUA, IUB on thestationary member I0 and on the other hand by the perpendicular faces IIA, .I IB on Vthe movable `.member I I.

Face. .I 0BA comprises one ofthe surfaces of an integrallyxfoltmed .flange I8 on `the channel shaped member I0, the flange I 8 having a slotted 'Y member II, member II having a slotted portion I ID one quarter waveV length deep which extends the full length of the member I I and cooperates with the adjvacentlypositioned face IIIA to form a choke to prevent the leakage of radio frequency which wouldotherwise flow through the other so-called B clearaneegor clearance space 2| between -.member I Land, face vI 0A.

The purpose of movingthe wave guide member I I with respect to theother wave guide member I0 is to alter the phase velocityand hence the wave length iny thejguide to thereby change the relative phase at vwhich the 'dipoles 25 arefed. This. change inuphasejaltersthe eiective direction of the radiated'combined wave front or beam '4 with the result that such beam scans through space when the wave guide member I I is moved.

A reflector 3l) having an L-shaped cross section is mounted on the guide member ID with its axis parallel to the axis parallel to the array of dipoles 25.

The wave guide member Ill, II mayA be approximatelyffourteen feet long or any other suit able length to produce `a radiation beam of desired width and is intended for use as a so-called precision type of antenna in ground controlled approach (GCA) systems. The wave guide member I supports a linear broad side array of a continuous line of approximately 180 or any other suitable number of dipoles 25. These dipoles may be suitably spaced over a sufficient length to produce a beam approximately .4 wide in elevation. These dipoles 25 are mounted along the wide side of the supporting wave guide member IG with their center conductors 25A extending into the guide as pickup probes. The insertion depth of 'the individual dipole probes 25A may be varied along the length of the array to produce a gable or other suitable distribution of power.

The dipole spacing is'apprcximately'one'half of the wave length and alternate dipoles are reversed, thus suppressing strong lobes which would otherwise exist at `approximately45 either side of the main lobe.

rlhe small percentage of power not picked up by the series of .probes 2`5A'is dissipated byan attached load or conventional absorber'unit'26 (Figure 6) to .prevent 'the formation of high standing waves due to reflection which would result in producing -side lobes. The absorber unit 26 may contain a mixture Vof graphite'and sand and may be equipped with external .heat radiating fins. This absorber` unit V2t is, of course, Vdisposed at the 'end of the wave guide IU, II opposite to that endto which` 'the'high frequency energy is fed.

The movable wave guide member'II is rsupported largely by anadjustably and 'releasably positioned series of bridge members '4I!A, `4I]B, 136C, 45D, 40E, dRliG, 40H,l 40J,`4DK, 'and'dL or any other number of such members as required 'and atequal spaced positions alongthe wave guide. These bridge members 40A-2I0Ij'are each of the same construction and, as shown in Figures 10, 12, and 20, are releasably 'mounted by bolts 33 on opposite finner vflange'n'lembers SI, 32. These bridge members rotatably support a pair of ball 'bearing members 42.0n corresponding axles 43. The outer surfaces, if desired, 'of these ball bearing members 42 are hardened and cooperate with the abutting hardenedlsurfaces on the bearing .plates or tracks 44,'"45 mounted by meansof boltsll'l 'on the underside'of'ftlie movable waveguide member II. Of Vimpor-tance is the fact that these bearing membersvcomprising the plates M; 45Jandth'e roller bearingfmembers 42 are'conveniently-.accessible fromothe bottom of the waveguide'after the coverm'ember 18 is removed so thatas 'these "bearing members or tracks become wornin use, they may be replaced in the field allowing the contiriueduse of the same .wave 'guide members I0, II. In other words, the vwave guide rn iembersll, 'II'are not susceptible of wear as are prior art wave guides.` This is a very desirable'feature since the manufacture ofsuchowave guide members requires much skill and 'great care linobserving dimensions.

Shims 58 of different thicknesses maybe'interposed between'such individual 'bridge-:mem-

bers 40A-40L and their supporting bridge flanges 3|, v32 to adjust the wave guide clearances 20', 2| atV the respective sections at which such bridge members are located.

In order to assure movement of the wave guide I I only in the direction indicated by the arrows I3 (Figure 13) a centrally disposed guide bearing 6|) (Figures 8 and 9) is provided.

The constructional features o f this guide bearing 60 are more clearly shown in Figures 1, 8 and 9. Such guide bearing 60 comprises a rectangular guide block 6I releasably attached to the guide member II by bolt 62 and a strap member 63 'attached by bolts 65 to the flanges 3|, 32, there being provided a pair of roller bearings 61, 68 rotatably and releasably mounted on a strap 63 for cooperation with the guide block 6I. This guide block 6| may be hardened to resist wear as well as the outer cooperating surfaces on the guide rollers 61, 68. It is apparent that this guide bearing 60 comprising essentially the elements 6|, 61, 68 and 63 may be conveniently replaced since all the elements are screw or bolt-fastened. The guide roller 61, V63 may be removed after removing their fastening nuts 61A, 68B, respectively.

The waveguide member II is reciproeated in the direction indicated by arrows I3 in Figure 13 upon rotation of the motor driven shaft 10 in Figures 2, 3 and 16, the rotary movement of shaft 10 being converted into movement of the bar 1I. The assembly shown in Figure 16 comprises a crank member 12 coupled to the shaft 10, an arm 13 adjustable in length and having one of its ends rotatably supported on the crankshaft 12 and the other of its ends journaled for rotation on the shaft 14 on the block 15 which is attached to the bar 1I by bolts 16, thus rotary movement of shaft 10 results in movement of the bar 1I in the direction indicated by the arrows 18 in Figure 16. Such movement of bar 1| alongthe longitudinal axis of the wave guide is converted into motion of the movable wave guide member Il in a direction rtransverse to the axis of the wave guide by pivotally connected pairs of link members 80, 8| located at stations A, B, C, D, El, and F in Figures 3, 4, 5, 6 and 13, or at as many stationsV as required by the length of the array.

The pairs of link members 80, 8| are connected to the longitudinal movable actuating bar 1I as shown in Figure 13. For this purpose, a locking bolt |00 passes through aligned apertures in the bar 1I, spacer I 0I and the central core of the ball bearing member |03 in one end of link pin 80 to lock these elements together by the releasable nut |05. The other end of link member 8| is bifurcated to receive the adjustably positioned extension 32A of flange 32. The bifurcated ends of link member 8| each receive a roller bearing member |05, |06, the central cores of which are locked together and to the flange extension 32A by the bolt |09 having the fas- -tened nut IIO thereon. Thus, the link member 8| may rotate about the axis of the bolt I 09. This axis of rotation which corresponds to the action of bolt |00 may be conveniently adjusted as explained in greater detail hereinafter by adjustment of the set screw III for purposes of adjusting the internal dimensions of the wave guide l0, I. 1

The outer end of link member 80 is provided with a bearing insert H2, the central core of on to clamp such central core to the guide member |I with the Vspacer ||5 clamped therebetween. It is thus apparent that the movable wave bar 1| and link assemblies 80, 8| are supported as a cantilever, the base or abutment for such cantilever being the adjustable extension 32A of flange 32. Incidentally, through the intermedi-ary of the link members 80, 8| the extension 32A supports a portion of the load of them movable wave guide member Il. However, the larger portion of the weight of wave guide member |I and the link assembly including links 80, 8| and bar 1| is supported on the bridge supported bearing structures 42, 44, 45 described in detail hereinabove. In other words, the main function of the adjustably positioned extension 32A of flange 32 is not to carry a load but to provide an adjustment whereby the distance between faces IDB and IIB of the Wave guide may be altered at the diierent sections A through F along the wave guide in such a manner that the cross section may be made uniform throughout the length of the wave guide. ments of the extension 32A, accomplished by adjustment of the set screws I I and locking screw 32D, is in a direction perpendicular to the direction in which theclearances 20, 2| are adjusted by providing shims 50 (Figure 10) These clearances 20, 2| are referred to herein as the B- clearances and are the spacing between cooperating L-shaped portions of the guide members I0, such cooperating L-shaped portions of the guide members I0, II having an end of a leg of one L-shaped portion spaced from theadjacent leg of the other cooperating portion by a distance termed hereinas the B-clearance and represented by the spacing or clearance 20, 2|.

The adjustably positioned extensions 32A, as perhaps best seen in Figure 14, is formed by slitting such ange at 32B and decreasing its cross section at 32C to allow easy movement of its free end and by the set screw |I|. In order to avoid vibration of the extension 32A and to hold its adjustment a locking screw 32D is provided to urge such extension 32A against the set screw I It is noted that there is such an adjustable flange 32A at each one of the stations A-F so that the adjustment may be made where needed.

It is thus apparent that when kthe actuating bar 1I is reciprocated, links 8| are rotated about an adjustable axis corresponding tothe axis of bolts |09 (Figure 13) to impart a reciprocation to the movable wave guide member I I in the direction indicated by the arrow I3, it being remembered that longitudinal movement of such guide member II in the direction of its axis is prevented by the centrally disposed guide 60 (Figures 2, 5 and 9).

In conventional manner, conventional angle coupling and capacitor and blanker switch units |20 (Figures 1 and 2) may be associated with the movable Wave guide member |I to provide synchronization of cathode ray beam sweeps and other purposes.

While the particular embodiments of the present invention have been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made without i departing from this invention in its broader aswhich is Vlocked to the Wave guide member II, by

the bolt- I4 having the fastening nut II5 therepects and, therefore, the aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of this invention.

Y I claim:

1. In a variable wave guide structure adapted Such adjustto propagate ultrafhigh frequency energy, and arranged to feed a plurality of spaced'dipoleal an elongated member` forming a relatively stationary portion of said wave guide through which prtions of said spaced dipoles extend toV serve as spaced pickup probes for energy propagated as radiation within said wave guide structure, the internal cross-section of said Wave guide being variable to alter the apparent wave length of such radiation to thereby change the relative phase at which the dipoles are fed toproduce a change in direction of the total energy radiatedfrom all of said dipoles, said elongated member having pairs of support surfaces spaced transversely thereof, a pluralityof bridge structures releasably mounted on corresponding pairs of `said support surfaces, a movable wave guide member cooperatively associated with said first waveguide member to form therewith the` internal space ofv the wave guide Within which said radiation is propagated, and said movable wave guide memberfbeing mounted for movement on. said bridge structure.

2. In a variable wave guide structure adapted to propagate ultra-high frequency energy and arranged to feed a plurality of spaced dipoles, said spaced dipoles each having a portion thereof extending Within said wave guide to serve as spaced pickup probes for energy propagatedy as radiation within said Wave guide structure, the internal cross-section of saidjwave guide structiue being variable to alter the apparent Wave length of such radiation to thereby, change the relative phase at which the dipoles are fed to produce a change in direction uof the total Yenergy radiated from all of the dipoles, said Wave guide structure including an elongated member having a pair of internally formed ilanges on opposite walls thereof extending substantially parallel in the longitudinal direction'of said VVelongated member, a movable Wave guide. section cooperatively associated with said elongated member to form a variable cross-section wave guide, a bridge structure releasably and adjustably mounted on said flanges, said movable, Wave guide section being mounted for lmovement on said bridge l.

structure, at least a-portion of one of` said flanges beingV supported asa centilever on said elongated member, said movable wave guide section being supported on the free end 'of 'said cantilever, and means disposed between thefree end of said cantilever and said elongated member to adjust the position of said cantilever with respect to said elongated member Yto thereby adjust the position of said movable wave guide section and crossseotional area of said waveguide.

3. In a variablewave guide structure adapted to propagate ultra-high frequency energy and arranged to feed a plurality of `spaced dipoles, said spaced dipoles having at least aV portion thereof extending with said wave guide structure to serve as spaced pickup probes for energy propagated as radiation within said Wave Vguide structure, the internal cross-.section of said Wave guide structure being variable to alter the apparent Wave length of such radiation to thereby change the relative phase at which the dipoles are fed to produce a change in direction of' the total energy radiated from all of said dipoles, said wave guide structure comprising: a relatively stationary wave guide member, a relatively movable Wave guide member cooperating with said relatively stationary wave guide member to form a substantially rectangular internal cross-sectional area of said Wave guide, means adjustably vsupporting said movable wave guide member for'adjustedmovement alongV oneaxis of said rectangular area, andmeans independent of the last mentioned meansfor adjustably supporting said` movable Wave guide member in adjusted positions along the other aXis of said rectangular area.

4. In a variable wave guide structure adapted to propagate ultra-high frequency energy and arranged to feed a plurality of spaced dipoles, said spaced dipoles having. at least a portion thereof extending into said wave guide to serve as pickup probesnfor energy propagatedas radiation within said wave guide structure, the internal cross-section of said guide structure being variable to alter the apparent wave length of said radiation to thereby change the relative phase at which the dipoles are fed to producea change in direction of the total energy radiated from all of the dipoles, said variable wave guide structure comprising: a relatively stationary elongated wave guide member, said stationary wave guide member having cantilever supporting members at different sections along its length, the free ends of said cantilever supporting members being movable to adjusted positions with respect to said stationary wave guide member, a movable wave guide member cooperatively associated with respect to the first mentioned stationary wave guide member to form said variable waveguide structure, ,said movable Wave. guide member being supported on said cantilever supporting members, and means for adjusting and maintaininginadjusted position said free ends of said cantilever supporting members to thereby adjustably position said movable wave guide member with respect to said stationary wave guide member to' align said movable Wave guide member with respect to the stationary waveguide member.

5. In a variable Wave guide. structure adapted to propagate ultra-high frequency energy and arranged to feed a plurality of spaced dipoles, said spaced dipoles having at least` a. portion thereof'extending into` said wave. guide' to serve as pickup probes for energyy propagatedas radiation within said wave guide structure, the internal cross-section of said guide structure being variable to alter the apparent Wave length. of said radiation to thereby change. the relative phase at which the dipoles are fed .to .produce a change in direction of the total energy radiated from all of the dipoles, said waveguide structure comprising: a relatively stationary wave guide member, a relatively movable. wave guide mem.- ber cooperatively associated with said stationary wave guide member to form therewith a ,variable cross-sectional wave guide, the cross-section `of said wave guide being rectangular, said rectangularcross-sectional area being defined bycooperating L-shaped portions of said stationary-and movable guide members with an end of 'a leg of one Vportion spaced lfrom the adjacent legi of Ythe other'portion a Vdistance termed the B-clearance between said guide members, said stationary wave guide Ymember havingmounted thereon, spaced along its length, a plurality of cantilever-supporting members, the free. ends of said cantilever members being adjustable inposition and supporting said movable guide member, means for moving the free ends of said cantilevers ina first direction corresponding to one of the axes of said rectangular area, said first direction being .perpendicular to the direction in which saidB-clearance is measured, means `for adjusting and maintaining in adjustedl position. the -freeends of said cantilever supporting members towthereby-ad-l just the position of said movable guide member 9- with respect to said stationary guide member along said first direction, and means supporting said movable guide member on said stationary guide member for adjustment in a 4direction perpendicular to said first directionand corresponding to the other longitudinal axis of said recternal cross-section of said guide structure being variable to alter the apparent wave length of said radiation to thereby change the relative phase at which the dipoles are fed to produce a change in direction of the total energy radiated from all of the dipoles, said wave guide structure comprising: a relatively stationary wave two spaced supporting members, one of said members being adjustably positioned with respect to said wave guide, means for adjusting said one supporting member and maintaining said one supporting member in adjusted position, a relatively movable guide member cooperatively associated with said stationary guide member to form a variable cross-sectional wave guide therewith, a bridge structure mounted on said supporting members, and means mounting said movable wave guide on said bridge member for movement thereon.

9. In a variable wave guide structure adapted topropagate ultra-high frequency energy and arranged to feed a plurality of spaced dipoles, said spaced dipoles having at least a portion thereof extending into said wave guide to serve as pickup probes for energy propagated as radiation within said wave guide structure, the internal cross-section of said guide structure being variable to alter the apparent wave length guide member and a movable guide member cooperating therewith, a Vpluralityjof Vadjustable supporting elements mounted on said stationary guide member at points therealong, means for adjusting the position of said supporting' members with respect to said` stationary guide member. said movable guidel member being movable on said supporting members, and cooperating wear-resistant surfaces disposed between said supporting members and said movable guide member.

7. In a variable Wave guide structure adapted to propagate ultra-high frequency energy and arranged to feed a plurality of spaceddipoles, said spaced dipoles having at least a portion thereof extending into said wave guide to serve as pickup probes for ener-gy propagated as radiation within said wave guide structure, the internal cross-section of said guide structurebeing variable to alterthe apparent wave length of said radiation to thereby change the relative phase at which the dipoles are fed to produce a change in direction of the total energy radiated from all of the dipoles, said wave guide structure comprising: a relatively stationary wave guide member having at least a pair of spaced supporting members thereon, a relatively movable wave guide section cooperatively associated with said stationary guide member to provide a wave guide of varying cross-sectional area, a bridge structure releasably supported on said supporting members, spacers of predetermined thickness between said bridge structure and said supporting members to adjust the position of said bridge structure with respect to said stationary guide member, and means supporting said movable guide member on said bridge member for movement thereon.

8. In a variable wave guide structure adapted to propagate ultra-high frequency energy and arranged to feed a plurality of spaced dipoles, said spaced dipoles having at least a portion thereof extending into said wave guideto serve as pickup probes for energy propagated as radiation within said wave guide structure, the internal cross-section of said guide structure being variable to alter the apparent wave length of said radiation to thereby change the relative phase at which the dipoles are fed to produce a change in direction of the total energy radiated from all of the dipoles, said wave guide structure comprising: a relatively stationary wave guide member having mounted thereon at least of said radiation to thereby change the relative phase at which the dipoles are fed to produce a change in direction of the total energy radiated from all of the dipoles, said wave guide structure comprising: a relatively stationary wave guide member, a relatively movable cooperating wave guide member to provide said guide structure of varying cross-sectional area, a` longitudinally movable bar extending substantially the length of said wave guide and parallel to the longitudinal axis of the wave guide, said relatively movable guide member being mounted for movement on said stationary guide member in a direction perpendicular to the longitudinal axis of the guide, said bar member being pivotally attached to said relatively movable guide member, an adjustable supporting member on said stationary guide member, a pivotal connection between said bar and said` adjustable supporting member, a bridge member releasably secured to said stationary guide member, and means mounting said movable guide member on said bridge member for movement thereon.

' 10. In a variable wave guide structure adapted to propagate ultra-high frequency energy and arranged to feed a plurality of spaced dipoles, said spaced dipoles having at least a portion thereof extendinginto said wave guide to serve as pickup probes for energy propagated as radiation within said wave guide structure, the internal cross-.section of said guide structure being variable to alter the apparent wave length of said radiation to thereby change the relative phase at which the dipoles are fed to produce a change Iin direction of the total energy radiated from allof the dipoles, a relatively stationary wave guide member, at least a pair of spaced supporting members on said stationary guide member, a bridge structure releasably mounted on said spaced supporting members, a relatively movable cooperating wave guide section movably mounted on said bridge structure to provide said variable wave guide, a relatively movable cooperating wave guide section movably mounted on said bridge structure, said bridge structure being adjustable in a first direction, a longitudinal movable bar member extending substantially parallel to the direction of said wave guide, means arranged td guide said movableV wave guide section in a direction perpendicular to the direction of said Wave guide, a pivoted link-connected bar to said movable wave guide section, a support on said stationary guide section adjustable in a direction perpendicular to said first direc- 11 Y tion, and said bar member being pivotally mounted on said adjustable support.

11. In a variable wave guide structure adapted to propagate ultra-high frequency energy and arranged to feed a plurality ofspaced dipoles, said spaced dipoles having at least a portion thereof extending into said Wave guide to serve as pickup probes for energy propagated as radiation Within said Wave guide structure, the internal cross-section of said guidestructurebeing variable to alter the apparent wave length of said radiation to thereby change the relative phase at which the dipoles are fed to produce a change in direction of the total energy radiated from all of the dipoles, said wave guide structure comprising: a relatively stationary wave guide section, and a cooperating relatively movable Wave guide section, means arranged to guide the movement of said movable section in a direction substantially perpendicular to the longitudinal axis of said wave guide, a plurality of independently adjustable supporting members mounted on said relatively stationary wave guide member and along its length, a longitudinally movable bar member movable substantially parallel to the longitudinal axis of said Wave guide, link means connecting said bar to said movable wave guide section and to said adjustable supporting members, a plurality of bridge members releasably supported at their ends with respect to said stationary Wave guide section and adapted to at least partially support said movable wave guide section for movement thereon.

12. The invention defined in claim 11, characterized by the fact that said plurality of bridge members are releasably mounted and are adjustable in position.

13. In a variable wave guide structure adapted to propagate ultra-high frequency energy and arranged to feed a plurality of spaced dipoles, said spaced dipoles having at least a portion thereof extending into said Wave guide to serve as pickup probes for energy propagated as radiation within said Wave guide structure, the internal crosssection of said guide structure being variable to alter the apparent wave length of said radiation to thereby change the relative phase at which the dipoles are fed to produce a change in direction of the total energy radiated from all of the dipoles,

said Wave guide structure comprising: a relatively l stationary guide member, a relatively movable wave guide member cooperatively associated with said stationary guide member to provide a Wave guidewith a variable rectangular cross-sectional area, each of said Wave guide members having cooperating L-shaped portions with an end of a leg of one portion spaced from the adjacent leg of the other cooperating portion by a distance termed the B-clearance, a supporting member releasably secured to said stationary Wave guide member, means mounting said movable wave guide member for movement on said supporting member, and means for adjusting the position of the supporting member to adjust said B-clearance.

14. In a variable wave guide structure adapted to propagate ultra-high frequency energy, an elongated member forming a relatively stationary portion of said Wave guide structure, the internal cross-section of said Wave guide being variable to alter the apparent Wave length of radiation propagated therein, said elongated member having pairs of support surfaces spaced transversely thereof, a plurality of bridge structures releasably mounted on corresponding pairs of said support surfaces, a movablewave guide member cooperatively associated with said rst Wave guide member to form therewith the internal space of the wave guide within which said radiation is propagated, and said movable wave guide member being mounted for movement on said bridge structure.

15. In a variable wave guide structure adapted to propagate ultra-high frequency energy, vthe internal cross-section of said Wave guide structure being variable .to alter the apparent Wave length of thev ultra-highfrequency energy propagatedltheren, said Wave guide structure including an elongated member having a pair of internally formed nanges. on opposite Wallsothereof extending substantially parallel in the longitudinal direction of said elongated member, a movablev Wave Aguidesection cooperatively associated with said elongated member to form a variable cross-section wave guide, a bridge structure releasably and adjustably mounted on said flanges, said movable wave guide section being mounted for movement on said bridge structure, at least a portion of one of said flanges being supported as a cantilever on said elongated member, said movable wave guide section being supported on the free end of said cantilever, and means dispose between the free end of said cantilever and said elongated member to adjust the position of said cantilever with respect to said elongated member to thereby adjust the position of said movable Wave guide section and the cross-sectional area of said Wave guide.

16. In a variable wave guide structure adapted to propagate high frequency energy as radiation, the internal cross-section of said wave guide structure being variable to alter the apparent wave length of such radiation, said Wave guide structure comprising: a relatively stationary Wave guide member, a relatively movable wave guide member cooperating with said relatively stationary wave guide member to form a substantially rectangular internal cross-sectional area of said wave guide, means adjustably supporting said movable wave guide member for adjustable movement along onev axis of said rectangular area, and means independent of the last mentioned means for adjustably supporting said movable Wave guide member in adjusted positions along the other axis of said rectangular area.

17. In a variable Wave guide structure adapted to propagate ultra-high frequency energy as radiation, the internal cross-section of said guide structure being variable. to alter the apparent wave lengthof said radiation, said variable Wave guide structureA comprising: a relatively stationai'yr elongated Wave guide member, said stationary wave guide member having cantilever supporting members at different sections along its length, the free ends of said cantilever supportingmembers being movable to adjusted positions with respect to said stationary wave guide member, a movable Wave guide member associated with respect to the first-mentioned stationary wave-guide member to form said variable wave. guide structure, Asaid movable vwave guide member being supported on said cantilever supporting members, and means for adjusting and maintaining in adjusted position said free ends of said cantilever supporting members to thereb y adjustably position said movable Wave guide member with respect to said stationary wave guide member to align said movable guide memler with respect to the stationary guide mem- 18. In a variable wave guide structure adapted to propagate ultra-high frequency energy as radiation, the internal cross-section of said guide structure being variable to alter the apparent wave length of said radiation, said wave guide structure comprising: a relatively stationary Wave guide member, a relatively movable wave guide member cooperatively associated with said stationary Wave guide member to form therewith a variable cross-sectional wave guide, the cross-section of said wave guide being rectangular, said rectangular cross-sectional area being dened by cooperating L-shaped portions of said stationary and movable guide members with an end of a leg of one portion spaced from the adjacent leg of the other portion a distance termed the B-clearance between said guide members, said stationary wave guide member having mounted thereon, spaced along its length, a plurality of cantilever supporting members, the free ends of said cantilever members being adjustable in position and supporting said movable guide member, means for moving the free ends of said cantilevers in a rst direction corresponding to one of the axes of said rectangular area, said first direction being perpendicular to the direction in which said B-clearance is measured. means for adjusting and maintaining in adjusted position the free ends of said cantilever supporting members to thereby adjust the position of said movable guide member with respect to said stationary guide member along said rst direction, and means supporting said movable guide member on said stationary guide member for adjustment in a direction perpendicular to said rst direction and corresponding to the 14 other longitudinal axis of said rectangular crosssectional area to adjust said B-clearance.

19. In a variable wave guide structure adapted to propagate high frequency energy as radiation, the internal cross-section of said guide structure being variable to alter the apparent wave length of said radiation, said Wave guide structure comprising: a relatively stationary guide member, a relatively movable wave guide member cooperatively associated with said stationary guide member to provide a wave guide with a variable rectangular cross-sectional area, each of said wave guide members having cooperative L-shaped portions with an end of a leg of one portion spaced from the adjacent leg of the other cooperating portion by a distance termed the B-clearance, a supporting member releasably secured to said stationary wave guide member, means mounting said movable wave guide meinber for movement on said supporting member, and means for adjusting the position of the supporting member to adjust said B-clearance.

KARL A. ALLEBACH.

REFERENCES orrnn The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 2,418,809 Albersheim Apr. 15, 1947 2,433,368 Johnson Dec. 30, 1947 2,453,414 De Vore Nov. 9, 1948 2,464,276 Varian Mar. 15, 1949 2,480,189 Irving Aug. 30, 1949 2,480,208 Alvarez Aug. 30, 1949 

